1. FIELD OF INVENTION
The present invention relates to apparatus and methods of dispensing and retrieving flexible pipe.
2. DESCRIPTION OF PRIOR ART
When wells are being drilled in remote areas fuel and fluid, such as water, for the drilling rig are supplied by temporarily laid flexible pipe. The flexible pipe is usually made from a suitable synthetic resin, such as polyethylene.
Although vehicle mounted reels and winding and control mechanisms for lengths of hose, pipe cable, wire and the like have long been known, these structures were not, so far as is known, readily adapted for use in connection with laying and retrieval of flexible pipe for drilling rigs. Flexible pipes of two miles and longer in length were often required for remote rigs. Additionally, weight became a problem for these lengths of flexible pipe. For example, 2 inch outside diameter polyethylene pipe weighs on the order of sixty pounds for each one hundred feet.
U.S. Pat. No. 3,995,355 discloses that a flexible pipe was laid and retrieved from reels or spools on the bed of a truck. During retrieval, the vehicle was stationary while reeling in the flexible pipe, and the pipe was cut or severed into a number of segments, each segment shorter in length than the contents of a spool. After each segment was pulled onto the spool, the truck was moved to a position near the next pipe segment. However, before the next pipe segment could be reeled onto the spool, attachment by fusion welding to the end of the pipe already on the reel was necessary. Since fifteen or twenty minutes is required to effect a satisfactory fusion weld, this retrieval technique was time consuming.